This invention relates to a technique for providing an inkjet recording apparatus wherein the inkjet recording apparatus can be switched into different states for recording, purging, standby, and air discharge, with a simple structure.
A conventional inkjet recording apparatus has an ink supply system. For example, in this system, ink is supplied through tubes from a main tank to a sub-tank provided on a carriage. This type of inkjet recording apparatus comprises a carriage and a main tank. The carriage carries a recording head and a sub-tank thereon. The recording head ejects ink from ejection nozzles and conducts recording on a recording medium. The sub-tank stores ink that is supplied to the recording head. The main tank stores ink that is supplied to the sub tank. When the ink in the sub-tank is decreased, additional ink is supplied to the sub-tank from the main tank.
Some of the inkjet recording apparatus of this type have a maintenance mechanism. Specifically, this type of inkjet recording apparatus is provided with an air-bubble remover at a standby position of the carriage. In this apparatus, accumulated air bubbles in an ink tank are removed by the air-bubble remover as follows. First, a lifting body is lifted by a horizontal movement of a cam. A valve rod is pushed up by a release rod. Suction paths respectively communicated with air-bubble reservoirs are opened by an opening-closing valve. Consequently the surfaces of the ink in the respective air-bubble reservoirs are raised by the positive pressure provided by an air pump. The accumulated air bubbles are discharged through the opening-closing valve while the air-bubble reservoirs are opened by the valve.
However, in the structure of the inkjet recording apparatus as described above, the lifting body and the release rod are respectively lifted by different lifting mechanisms. This kind of structure increases the number of components used in the inkjet recording apparatus. Additionally, these lifting mechanisms need to be controlled independently from each other. Therefore, the structure of the inkjet recording apparatus becomes complicated.
The present invention was made in consideration of the above and other inconveniences. It would be desirable that an inkjet recording apparatus is provided with a technique wherein the state of the inkjet recording apparatus is changed for recording, purging, standby, and air discharge, through a simple structure.